Online conferencing (a.k.a., web conferencing and/or internet conferencing) systems have an array of capabilities including voice/video communications, instant messaging, data/application sharing, and white-boarding. These online collaborative service systems enable users to engage in communication sessions to exchange different types of communication media, such as voice data, video data, content sharing, and combinations thereof. Some conferencing systems enable users to share and collaborate in creating and modifying documents or other shared content. Online conferencing typically allows real-time point-to-point communication as well as multicast communications (i.e., from one sender to many receivers). Some services offer data streams of voice and/or video chat to be shared simultaneously, across geographically dispersed locations. Applications for online conferencing include meetings, training events, lectures, and presentations.